Alternative manufacturing: Electric discharge machining of low conductivity materials

Chicago, Illinois – Thanks to advances in electronics and numeric controls, unconventional technologies such as electric discharge machining (EDM) have recently evolved into a highly effective and reliable method for processing difficult-to-machine materials, independently of their hardness and mechanical resistance, and with the only requirement of having a good electrical conductivity. However, the present study shows that EDM can also be upgraded for the machining of materials with low electrical conductivity by enhancing the EDM pulse generator sources.

First, this enables the spark ignition and sustaining conditions in the machining gap to become close to those obtained in standard systems by compensating the resistive losses in the machined materials. Second, the machining pulse itself is designed to optimize the removal mechanism in the material, whether by melting, evaporation or mechanical thermo-shock. The applications potential of such new adapted systems is shown by describing the process results of promising but challenging materials for high-efficiency aerospace component manufacturing, such as ceramic matrix or carbon-fiber based composites. Further evidence is presented via the analysis of removal rates, surface integrity and mechanical characteristics of the machined surfaces.

This presentation is based on work developed by Dr. Roberto Perez. Dr. Perez is responsible for Applied and Collaborative Research at GF Machining Solutions. He received his PhD from the University of Geneva and a MBA from The Open University (UK). After joining the R&D department of Charmilles Technologies in 2000 as a research engineer, he has led various projects for improving the performance of electric discharge machines (EDM) in terms of productivity, accuracy and enhancing the capabilities of the technology for producing surface coatings and processing new materials such as ceramics, aerospace and medical alloys. His activities are currently focused on the development of innovative EDM modules and processes in collaboration with academic partners and key customers worldwide mainly in the mold and die, aerospace and medical segments, and in coordination with the wider GF Machining Solutions product portfolio of high speed milling and laser technologies.

About the speaker
Ken Baeszler is the Aerospace Market Segment Manager at GF Machining Solutions. He has had various responsibilities within that organization for over 20 years, including the development of technology for a variety of materials and industries. His lengthy involvement with the machine tool industry has allowed him to witness several generations of technological improvements, and his current passion is to communicate these improvements to the manufacturing industry.